[Dericali]

A small question in case anyone can help.

I shoot mainly with AF.C and select (spot and sometimes 9 points /zone). Sometimes when I look over photos later I find that the subject is out of focus e.g. the background. (Not too frequently though). I'm wondering if there is any easy way to use the exif data to determine where I had my focus point, so I can try to figure out whether there is a mistake I'm making and/or something else, and how to reduce errors through better technique.

Another question in case anyone has a similar experience: Sometimes when shooting with the DFA 24-70 it goes completely haywire hunting for focus and can't find any focus point, even when nothing has changed in the scene (this has been when doing outdoor portrait photography with a lot of bright light, so maybe this is a factor). I hold down the backfocus button and if I take photos it shows everything out of focus. Eventually corrects. Episodes like this happen sort of seldom (say once every 500 shots), but of course it tends to be when I'm doing something important.

[Unregistered User 8]

What subjects are you shooting in AF-C? Also have you got AF-C set for focus priority?

[joergens.mi]

use the exiftool 10.50 from Phil Harvey ExifTool by Phil Harvey

example; exiftool "Jazz_(Apfel)_jm28435_ji.jpg" >tt,asc

hand have look the lines starting with AF Points in the file tt.asc

[Dericali]

This is an example (not edited) - break-dancing kid in Alexandria, Egypt. Focus point appears to be somewhere on the pigeon in the background. He was moving towards me.

@Pjv

I think I was using release priority, which may be the problem, though I was under the impression that AF.C would recheck focus in each frame continuously.

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[Unregistered User 8]

I think I was using release priority, which may be the problem,

This may be your issue. Release priority will start shooting whether in focus or not. Focus priority will not release the shutter until focus is achieved. Also, have you checked if your lens needs AF adjustment? Good luck.

[clackers]

For accuracy, you need to use a single focus point (not some auto mode - there might be another point where a nice lamppost forms a stronger line that gets its attention), press the shutter half-way, confirm focus with the beep, and press all the way.

For the subject above, who is backlit, the eyes have a similar darkness to the rest of the face, so unambiguous lines to instead put your focus point on include his eyebrow and the white strip of his top's collar.

[MadMathMind]

For the subject above, who is backlit, the eyes have a similar darkness to the rest of the face, so unambiguous lines to instead put your focus point on include his eyebrow and the white strip of his top's collar.

This. Backlighting will make a mess of PDAF focusing. I've shot stuff with really strong backlights and getting the camera to focus is a nightmare--it just spins back and forth.

You always need to give the camera something to focus on, something with contrast. Backlighting ruins local contrast so it really makes the focus system struggle. Look for things with big jumps, like the seam between the white part of his jacket and the red part. That can be a great focus point if you have enough DoF to get his face.

[Dericali]

Thanks. The first shot in the sequence was in focus, but as he started coming towards me, obviously the camera wasn't refocusing (?).

I rechecked my settings and my '1st Frame Action in AF.C' setting is Focus-priority, my 'Action in AF.C Cont' is 'auto' (so I guess I should move this to Focus-priority), and my Hold AF status is 'High'.

I was shooting f6.3 and 1/1000 ( had just been shooting some people jumping into the water) so I probably should have adjusted for wider DoF.

For accuracy, you need to use a single focus point (not some auto mode - there might be another point where a nice lamppost forms a stronger line that gets its attention), press the shutter half-way, confirm focus with the beep, and press all the way .

Thanks. I find that occasionally the single focus point isn't ideal - specially with fast moving small objects, such as birds, because if the subject moves out of the single point area, the lens goes hunting. If you don't have a focus limiter on the lens, this can take half a second or more for it to find the focus again. If you have the 9 point zone select then you seem to have more margin for error when you're tracking something fast-moving. I guess if I was better at tracking though I wouldn't need this.

[clackers]

Thanks. I find that occasionally the single focus point isn't ideal - specially with fast moving small objects, such as birds, because if the subject moves out of the single point area, the lens goes hunting. If you don't have a focus limiter on the lens, this can take half a second or more for it to find the focus again. If you have the 9 point zone select then you seem to have more margin for error when you're tracking something fast-moving. I guess if I was better at tracking though I wouldn't need this.

Exactly, Dericali.

Tracking is a skill we photographers must master to shoot sports and wildlife.

If Uncle Bob gets asked to do a nephew's soccer game because he owns a pro camera, it can be an embarrassing exercise if Bob has spent years shooting flowers. I would encourage everyone (including Internet camera reviewers) to practice panning with a car or bicycle as a target, and to be very smooth, rotating through the hips, and read the manual or ask people on this forum about the best settings in the AF modes for their situation.

For planes or birds against an empty sky, I will use 9 point Auto myself. The only thing that can be focused on can be the subject.

For your pic of the guy above, the danger with 9 point Auto is that the outstretched hand may be calculated by the camera to be closer than the face, and that's the point it will use.

[pschlute]

The other thing you should do is look on the viewfinder overlay and see what the camera is focussing on...the red squares that will illuminate to show which focus points it is using.